New Delhi, July 2 -- LUXEMBOURG - The European Union's highest court rejected Google's final appeal Thursday against a €4.1 billion antitrust fine, cementing a penalty eight years in the making and establishing the legal foundation for a new wave of competitor damage claims that could extend the case's commercial consequences well beyond the fine itself.

The Court of Justice of the European Union confirmed that Alphabet Inc.'s Google unit had used its Android mobile operating system as an instrument of illegal market dominance in search, upholding the core findings of a European Commission decision from July 2018. The original penalty, €4.3 billion, the largest competition fine the Commission had ever levied at the time, was ...